Atraumatic medical device

ABSTRACT

A medical device, and related method, for manipulating material, such as calculi, within a patient&#39;s body includes a handle, a sheath, a retrieval basket, and a retainer coupled to the distal end of the retrieval basket. The retrieval basket includes a plurality of legs, each of which includes an intermediate portion located at the distal end of the retrieval basket. The retainer secures at least the intermediate portion of one of the plurality of legs to the intermediate portion of another of the plurality of legs.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.10/941,419, filed Sep. 15, 2004 (now U.S. Pat. No. 7,824,415), which isincorporated herein by reference in its entirety.

TECHNICAL FIELD

The invention generally relates to medical devices for retrieving,trapping, and sweeping material within a patient's body. Moreparticularly, the invention relates to medical devices that haveatraumatic distal ends. The atraumatic distal ends minimize the chanceof damaging surrounding tissues during the use of the devices andenhance the ability of the devices to manipulate material (e.g.,calculi) disposed or lodged in areas that are difficult to access in thebody.

BACKGROUND

A medical device can be used to retrieve calculi from a body. One typeof known medical device has a sheath and a retrieval basket that ismoveable in and out of the sheath. Typically, the retrieval basket isconstructed by joining multiple legs together, both at a base of theretrieval basket and at a distal end of the retrieval basket, such thata “cage” is formed. At the distal end of the retrieval basket, theindividual legs are joined by, for example, soldering or welding. Aprotruding tip at the distal end of the retrieval basket results.

In a clinical application, this protrusion or outward projection at thedistal end of the retrieval basket may poke tissue and cause tissuetrauma. Further, the protruding tip may hinder the ability to accesscalculi located within some areas of the body.

Improved devices and methods for manipulating material within a bodyare, therefore, needed.

SUMMARY OF THE INVENTION

The invention generally relates to devices and methods for themanipulation of material within the body of a patient. The devices andmethods allow access to, and/or intimate contact with, the areas of thebody where the material to be manipulated resides. The devices andmethods also generally avoid damaging the lining of the body tract inthose areas. One embodiment of a device according to the inventionincludes a retrieval basket, with a substantially atraumatic distal end,that is capable of sweeping, capturing and releasing biological and/orforeign material (e.g., calculi). The retrieval basket may be used, forexample, as a sweeper, a urological retrieval basket, as an endoscopicretrieval basket, or as a lithotripsy-assist device.

In one aspect of the invention, a medical device includes a handle, asheath joined to the handle, a retrieval basket, and a retainer coupledto the distal end of the retrieval basket. The sheath includes a lumenand the retrieval basket includes a proximal end, a distal end, and aplurality of legs. Each of the plurality of legs includes a first end, asecond end, and an intermediate portion. The first and second ends ofthe plurality of legs are located at the proximal end of the retrievalbasket and the intermediate portion of each of the plurality of legs islocated between the first and second ends of the leg and at the distalend of the retrieval basket. The retainer secures at least theintermediate portion of one of the plurality of legs to the intermediateportion of another of the plurality of legs. The intermediate portionsof the legs may cross one another, or they may be side-by-side, whilebeing secured together by the retainer. The retrieval basket achieves acollapsed position when restrained in the lumen of the sheath and anexpanded position when unrestrained by the lumen of the sheath.

Various embodiments of this aspect of the invention include thefollowing features. The retainer may include at least two bands, which,in one embodiment, are made of a heat shrink material. In anotherembodiment, the retainer includes a plurality of tubes and each tubeincludes a first end, a second end, and a hollow passageway extendingfrom the first end to the second end. Each of the plurality of tubes mayalso include an intermediate section and at least the intermediatesection of one of the plurality of tubes may intersect the intermediatesection of another of the plurality of tubes. In one embodiment, atleast the hollow passageway of one of the plurality of tubes is in fluidcommunication with the hollow passageway of another of the plurality oftubes. The plurality of tubes may be made of a heat shrink material.

In yet another embodiment, the retainer includes a knob. The knob may beinjection molded to the distal end of the retrieval basket.Alternatively, the knob may be heat shrunk to the distal end of theretrieval basket. In yet another embodiment, the knob includes anadhesive. In still another embodiment, the retainer includes a firstmember, which includes a plurality of risers, and a second member. Inone embodiment, the first member is coupled to the second member.

In further embodiments, the retainer includes a lumen and a plurality ofopenings in fluid communication with the lumen. The retainer may bearch-shaped or, alternatively, cylindrical-shaped. Additionally, in oneembodiment, the intermediate portion of at least one of the plurality oflegs of the retrieval basket includes a connecting surface. Theconnecting surface may include at least one notch.

In another aspect, the invention relates to a method of manipulating amaterial within a body. The method includes inserting a medical device,as described above, into the body, positioning the retrieval basketproximate to the material to be manipulated with the retrieval basket inthe expanded position, capturing or sweeping the material with theretrieval basket, and withdrawing the retrieval basket from the body toremove or dislodge the material from or within the body. In oneembodiment of this aspect of the invention, the material includes acalculus.

The foregoing and other objects, aspects, features, and advantages ofthe invention will become more apparent from the following descriptionand from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. Also, the drawings are notnecessarily to scale, emphasis instead generally being placed uponillustrating the principles of the invention.

FIG. 1 is a schematic side view of a medical device with a retrievalbasket in an expanded position according to an illustrative embodimentof the invention.

FIG. 2 is a schematic side view of the illustrative medical device ofFIG. 1 with the retrieval basket in a collapsed position.

FIG. 3 is a perspective view of a distal end of a retrieval basketaccording to an illustrative embodiment of the invention.

FIG. 4 is a plan view of a retainer according to an illustrativeembodiment of the invention.

FIG. 5 is an end view of the illustrative distal end of the retrievalbasket of FIG. 3.

FIG. 6 is a perspective view of a distal end of a retrieval basketaccording to another illustrative embodiment of the invention.

FIG. 7 is a schematic perspective view of a distal end of a retrievalbasket according to another illustrative embodiment of the invention.

FIG. 8 is a top view of a retainer according to another illustrativeembodiment of the invention.

FIG. 9 is a schematic perspective view of a distal end of a retrievalbasket according to another illustrative embodiment of the invention.

FIG. 10 is a schematic perspective view of a distal end of a retrievalbasket according to another illustrative embodiment of the invention.

FIG. 11 is a perspective view of a distal end of a retrieval basketaccording to another illustrative embodiment of the invention.

FIG. 12 is a schematic perspective view of the illustrative distal endof the retrieval basket of FIG. 11 according to one embodiment of theinvention.

FIG. 13 is a schematic perspective view of the illustrative distal endof the retrieval basket of FIG. 11 according to another embodiment ofthe invention.

FIG. 14 is a fragmented perspective view of a distal end of a retrievalbasket according to another illustrative embodiment of the invention.

FIG. 15 is a fragmented perspective view of a distal end of a retrievalbasket according to another illustrative embodiment of the invention.

FIG. 16 is a schematic assembled perspective view of the illustrativedistal end of the retrieval basket of FIG. 14.

FIG. 17 is a schematic perspective view of a distal end of a retrievalbasket according to another illustrative embodiment of the invention.

FIG. 18 is a perspective view of a retainer according to anotherillustrative embodiment of the invention.

FIG. 19 is an end view of the illustrative retainer of FIG. 18.

FIG. 20 is a schematic perspective view of a distal end of a retrievalbasket according to another illustrative embodiment of the invention.

FIG. 21 is a schematic perspective view of a distal end of a retrievalbasket according to another illustrative embodiment of the invention.

FIG. 22 is a schematic perspective view of a retainer according toanother illustrative embodiment of the invention.

FIG. 23 is a schematic side view of the illustrative retainer of FIG.22.

FIG. 24 is a schematic perspective view of a distal end of a retrievalbasket according to another illustrative embodiment of the invention.

FIGS. 25-28 illustrate the steps in a clinical application of themedical device according to an illustrative embodiment of the invention.

DESCRIPTION

In general, the invention pertains to devices and methods relating tothe manipulation of material within the body of a patient. The medicaldevice of the present invention may be used to trap, sweep, and/orretrieve materials within the body of a patient.

FIG. 1 depicts a medical device 100 according to an illustrativeembodiment of the invention. As shown, the medical device 100 includes aproximal end 104 (i.e., an end that is closest to an operator of themedical device 100), an opposite distal end 108, a handle 112, a sheath116, a retrieval basket 120, and a retainer 124. The handle 112 islocated at the proximal end 104 of the medical device 100 and has,itself, a proximal end 128 and a distal end 132. An actuating mechanism134 is positioned on the handle 112. For its part, the sheath 116 has aproximal end 136, a distal end 140, and a longitudinally disposed lumen144 that extends from the proximal end 136 to the distal end 140. Anelongated member 148, such as, for example, a tube, a sheath, a cable, acoil, a shaft, a guidewire, or a mandril wire, axially extends in thelumen 144 of the sheath 116. The elongated member 148 has a proximal end152 and a distal end 156 that couples to a base 160 of the retrievalbasket 120. In some embodiments, the elongated member 148 also has alongitudinally disposed lumen (not shown). The lumen of the elongatedmember 148 may be adapted to accommodate, for example, an optical fiberfor visualization, and/or a laser fiber for stone destruction. In oneembodiment, the proximal end 136 of the sheath 116 attaches to thedistal end 132 of the handle 112 and the proximal end 152 of theelongated member 148 couples to the actuating mechanism 134 of thehandle 112. Alternatively, the proximal end 136 of the sheath 116couples to the actuating mechanism 134 of the handle 112 and theproximal end 152 of the elongated member 148 attaches to the distal end132 of the handle 112.

Referring still to FIG. 1, the base 160 of the retrieval basket 120 islocated at a proximal end 162 of the retrieval basket 120. A distal end166 of the retrieval basket 120 is located opposite to the proximal end162, i.e., the distal end 166 is further from the operator than theproximal end 162. In general, a plurality of legs 164 form the retrievalbasket 120. For example, in one embodiment, the retrieval basket 120 mayhave two legs 164, such as a first leg 164A and a second leg 164B, asshown. The legs 164 may be made from a variety of resilient materials,such as, for example, metal or metal alloys (e.g., nickel-titanium,stainless steel, etc.). Alternatively, the legs 164 may be made fromplastic or a combination of metal, metal alloys, and plastic. As shown,in one embodiment, each of the legs 164A, 164B has a first end 168, anintermediate portion 172, and a second end 176. Each of the legs 164A,164B forms a loop. Accordingly, both the first ends 168 and the secondends 176 of the legs 164 are located at the base 160 of the retrievalbasket 120 (i.e., at the proximal end 162 of the retrieval basket 120)and couple to each other or to the distal end 156 of the elongatedmember 148. The intermediate portions 172 of the legs 164 are locatedbetween the first ends 168 and the second ends 176 of the legs 164.Accordingly, the distal end 166 of the retrieval basket 120 includes atleast a portion of the intermediate portions 172 of the legs 164. Asexplained in greater detail below, the retainer 124 is located at thedistal end 166 of the retrieval basket 120 and secures the intermediateportion 172A of the leg 164A to the intermediate portion 172B of the leg164B.

Operation of the actuating mechanism 134 by an operator (e.g., aphysician) causes the retrieval basket 120 to achieve a collapsedposition, as shown in FIG. 2, or an expanded position, as shown inFIG. 1. Referring to FIG. 2, in one embodiment, the retrieval basket 120is restrained, in the collapsed position, within the lumen 144 of thesheath 116. The retrieval basket 120 may be reciprocally moved betweenthe collapsed position shown in FIG. 2 to the expanded position shown inFIG. 1. In the expanded position shown in FIG. 1, the legs 164 of theretrieval basket 120 extend beyond the distal end 140 of the sheath 116.

In the illustrative embodiments of FIGS. 1 and 2, the retrieval basket120 alternates between the collapsed position illustrated in FIG. 2 andthe expanded position illustrated in FIG. 1 by slideable movement of theelongated member 148 in the lumen 144 of the sheath 116. For example, byproximally withdrawing the actuating mechanism 134, the operatorwithdraws the elongated member 148 and restrains the retrieval basket120 in the lumen 144 of the sheath 116. The retrieval basket 120 therebyachieves the collapsed position. By distally advancing the actuatingmechanism 134, the operator advances the elongated member 148 andpositions the retrieval basket 120 beyond the distal end 140 of thesheath 116. The retrieval basket 120 opens and expands to achieve theexpanded position.

Alternatively, according to another embodiment of the invention (notshown), an operator moves the retrieval basket 120 between the collapsedand expanded positions by distally advancing or proximally withdrawingthe sheath 116 over a stationary elongated member 148 and the retrievalbasket 120. For example, by distally advancing the actuating mechanism134, the operator advances the moveable sheath 116 over the stationaryelongated member 148 and the retrieval basket 120, thereby collapsingthe retrieval basket 120 within the lumen 144 of the sheath 116. Byproximally withdrawing the actuating mechanism 134, the operatorwithdraws the moveable sheath 116 and exposes the retrieval basket 120beyond the distal end 140 of the sheath 116. The retrieval basket 120opens and expands to achieve the expanded position.

In general, both types of elongated member/sheath movementconfigurations and related handle mechanisms are known, and can be seenin existing product designs available from, for example, BostonScientific Corporation (Natick, Mass.).

FIG. 2 depicts the medical device 100 with the retrieval basket 120 in acollapsed position according to an illustrative embodiment of theinvention. In this embodiment, while the retrieval basket 120 iscollapsed and restrained within the lumen 144 of the sheath 116, anoperator inserts the distal end 140 of the sheath 116 into the body of apatient. The operator advances the distal end 140 of the sheath 116 toan anatomical site where the material to be manipulated is located(e.g., a calculus in the ureter). By placing the retrieval basket 120 inits open/expanded position, as illustrated in FIG. 1, the operatorpositions the retrieval basket 120 adjacent the material to be retrievedand maneuvers the retrieval basket 120 to entrap or capture the materialwithin the retrieval basket 120. By proximally withdrawing the elongatedmember 148 or, alternatively, by distally advancing the sheath 116, theoperator positions the proximal portion of the retrieval basket 120within the lumen 144 of the sheath 116. Consequently, the legs 164 ofthe retrieval basket 120 close around the material and secure thematerial within the retrieval basket 120. According to one embodiment ofthe invention, the sheath 116, the retrieval basket 120, and thecaptured material are withdrawn from the patient's body. In analternative embodiment, the captured material is fragmented by alithotriptor, such as, for example, a laser or a mechanicallithotriptor. The sheath 116, the retrieval basket 120, and the capturedmaterial are then removed from the patient's body. Alternatively, theoperator may also use the medical device 100 to dislodge or sweepmaterial from a first anatomical site, for example, a tortuous bodytract, to a second anatomical site where the material may be more easilyremoved or destroyed.

Referring again to FIG. 1, the retainer 124 is positioned at the distalend 166 of the retrieval basket 120. The general purpose of the retainer124 is to join and secure together the intermediate portions 172 of thelegs 164 at the distal end 166 of the retrieval basket 120. In oneembodiment, the intermediate portions 172 of the legs 164 cross oneanother at the distal end 166 of the retrieval basket 120, where theyare secured by the retainer 124. In another embodiment, the retainer 124holds the intermediate portions 172 of the legs 164 side-by-side at thedistal end 166 of the retrieval basket 120. In general, the retainer 124has an atraumatic structure. Specifically, the retainer 124 is devoid ofany outward projections or protrusions that might cause injury or traumato tissue. There is, therefore, no impediment to contacting the distalend 166 of the retrieval basket 120 directly and intimately with tissue.

FIG. 3 depicts a perspective view of a distal end 166 of a retrievalbasket 120, including the retainer 124, according to an illustrativeembodiment of the invention. As shown, in the illustrative embodiment,the retainer 124 includes two bands 184A, 184B. Alternatively, theretainer 124 may include one band 184 or any number of bands 184. Asillustrated in FIG. 4, in one embodiment, the band 184 is substantiallyelliptical in shape, enclosing a lumen 188. Alternatively, the band 184may assume other shapes which enclose a lumen 188.

In one embodiment, referring again to FIG. 3, the bands 184 areconstructed of a heat shrink material, such as, for example,polytetrafluoroethylene (PTFE) or a cross-linked polyolefin. Theintermediate portions 172 of the legs 164 pass through the lumen 188 ofone or more bands 184. As such, the bands 184 join and secure togetherthe intermediate portions 172 of the legs 164 at the distal end 166 ofthe retrieval basket 120.

In one feature of this embodiment of the invention, referring now toFIG. 5, the intermediate portions 172A, 172B of the legs 164A, 164Bcross one another at a crossing point 192 at the distal end 166 of theretrieval basket 120. In this embodiment, for example, the bands 184A,184B are offset by approximately 90 degrees from one another. Each band184A, 184B encircles a portion of the intermediate portion 172 of eachleg 164, and bands 184A, 184B together form an X-shape. Accordingly, theintermediate portion 172 of each leg 164 passes through the lumen 188 ofeach band 184.

In another embodiment, referring now to FIG. 6, a portion of theintermediate portions 172A, 172B of the legs 164A, 164B areside-by-side, but do not cross one another, at the distal end 166 of theretrieval basket 120. In this embodiment, for example, the bands 184A,184B are offset by approximately 90 degrees from one another, andtogether form an X-shape. Only the first band 184A encircles a portionof the intermediate portion 172 of the legs 164A and 164B. Accordingly,the intermediate portion 172 of each leg 164A, 164B passes through thelumen 188A of the first band 184A. The second band 184B encircles thefirst band 184A, but not the intermediate portion 172 of any of the legs164A, 164B. The intermediate portions 172 of the legs 164 do not crossone another and, therefore, the distal end 166 of the retrieval basket120 illustrated in FIG. 6 has a lower profile than the distal end 166 ofthe retrieval basket 120 illustrated in FIG. 5. In another embodiment,the distal end 166 of the retrieval basket 120 includes only the band184A.

FIG. 7 depicts a distal end 166 of a retrieval basket 120, including aretainer 124, according to another illustrative embodiment of theinvention. According to one feature of this embodiment, the retainer 124at the distal end 166 of the retrieval basket 120 includes two tubes196A, 196B. Alternatively, if the retrieval basket 120 includes morethan two legs 164, the retainer 124 may include more than two tubes 196.

FIG. 8 depicts a retainer 124 according to another illustrativeembodiment of the invention. According to the illustrative embodiment,each tube 196A, 196B of the retainer 124 includes a first end 200, asecond end 204, and a hollow passageway 208 that extends from the firstend 200 to the second end 204. The hollow passageway 208A of the firsttube 196A is in fluid communication with the hollow passageway 208B ofthe second tube 196B. The first tube 196A is offset from the second tube196B by approximately 90 degrees. The intermediate section 212A of thefirst tube 196A intersects the intermediate section 212B of the secondtube 196B. Accordingly, the retainer 124 is X-shaped.

Referring again to FIG. 7, in one embodiment, a portion of theintermediate portion 172A of the first leg 164A passes through thehollow passageway 208A of the first tube 196A, from its first end 200Ato its second end 204A. A portion of the intermediate portion 172B ofthe second leg 164B passes through the hollow passageway 208B of thesecond tube 196B, from its first end 200B to its second end 204B. Theintermediate portions 172A, 172B of the legs 164A, 164B cross oneanother at the distal end 166 of the retrieval basket 120.

In an alternative embodiment, referring now to FIG. 9, a portion of theintermediate portion 172A of the first leg 164A passes through both asegment 232A and a segment 236B of the hollow passageways 208A, 208B ofthe tubes 196A, 196B, respectively. Similarly, the intermediate portion172B of the second leg 164B passes through both a segment 232B and asegment 236A of the hollow passageways 208B, 208A of the tubes 196B,196A, respectively. The intermediate portions 172A, 172B of the legs164A, 164B are side-by-side, but do not cross one another, at the distalend 166 of the retrieval basket 120.

In yet another embodiment, referring now to FIG. 10, the second end 176of each leg 164 is located at the distal end 166 of the retrieval basket120, rather than at the base 160 of the retrieval basket 120, asdescribed above with reference to FIG. 1. Accordingly, no individual leg164 forms a loop. In a particular embodiment, the retrieval basket 120includes four such legs 164. Alternatively, the retrieval basket 120 mayinclude any number of such legs 164. As illustrated, according to thisembodiment, the second end 176 of each leg 164 is positioned in asegment of the hollow passageway 208 of one of the tubes 196.

In one embodiment, the tubes 196 are made of a heat shrink material,such as, for example, PTFE or a cross-linked polyolefin. According toanother embodiment of the invention, as illustrated in FIGS. 7 and 9,the intermediate portion 172 of each leg 164 includes a modifiedconnecting surface, such as, for example, a notch 240. Alternatively, asillustrated in FIG. 10, the second end 176 of each leg 164 includes thenotch 240. Once the legs 164 are placed into the hollow passageways 208of the tubes 196, as described above, heat is applied to the tubes 196.The heat causes the tubes 196 to shrink around the intermediate portions172 of the legs 164, or, alternatively, around the second ends 176 ofthe legs 164. The retainer 124 is thereby secured to the distal end 166of the retrieval basket 120. The notches 240 in the intermediateportions 172 of the legs 164, or, alternatively, at the second ends 176of the legs 164, allow the legs 164 to be more securely attached to theretainer 124 at the distal end 166 of the basket 120.

The length of the tubes 196, or, alternatively, the portion of the legs164 covered by the tubes 196, may be varied to suit a particularclinical application. For example, to provide the retrieval basket 120with heat resistant and/or laser resistant properties, longer tubes 196made of a heat shrink material are used to cover greater portions of thelegs 164 than is otherwise necessary to join the intermediate portions172 of the legs 164 together. In other words, to provide the retrievalbasket 120 with heat resistant and/or laser resistant properties, thetubes 196, in one embodiment, extend along the length of the legs 164,from the distal end 166 of the retrieval basket 120 substantiallytowards the proximal end 162 of the retrieval basket 120.

FIG. 11 depicts a distal end 166 of a retrieval basket 120 according toanother illustrative embodiment of the invention. In this embodiment,the retainer 124 at the distal end 166 of the retrieval basket 120includes a knob 244. In one embodiment, the knob 244 is made from, forexample, metals, metal alloys, or polymers. The polymers may include,for example, high density polyethylene (HDPE), nylon, or any otherbiocompatible thermoplastic. In one embodiment, the knob 244 isinjection molded to the intermediate portions 172 of the legs 164 at thedistal end 166 of the retrieval basket 120. In another embodiment, theknob 244 is heat shrunk to the intermediate portions 172 of the legs 164at the distal end 166 of the retrieval basket 120. In yet anotherembodiment, the knob 244 is an adhesive, such as, for example, a drop ofultra violet curing glue or a drop of cyanoacrylate. The knob 244 isshaped so that it has no outward projections or protrusions that mightcause injury or trauma to a patient's tissue.

In one embodiment of the knob 244, referring now to FIG. 12, theintermediate portions 172 of the legs 164 are first crossed before theknob 244 is injection molded, heat shrunk, or adhered to the distal end166 of the retrieval basket 120. Alternatively, as illustrated in FIG.13, the intermediate portions 172 of the legs 164 are side-by-side,rather than crossing one another, at the distal end 166 of the retrievalbasket 120. Accordingly, the distal end 166 of the retrieval basket 120illustrated in FIG. 13 has a lower profile than the distal end 166 ofthe retrieval basket 120 illustrated in FIG. 12.

FIG. 14 depicts a distal end 166 of a retrieval basket 120 according toanother illustrative embodiment of the invention. The retainer 124 atthe distal end 166 of the retrieval basket 120 includes a first member248 and a second member 252. The first and second members 248, 252 maybe made, for example, from polymers, such as high density polyethylene(HDPE), nylon, or any other biocompatible thermoplastic. In theembodiment shown, the first member 248 includes an inner face 254 andtwo risers 256. Alternatively, the first member 248 may include anynumber of risers 256. A riser 256 is a projection that extendssubstantially vertically from the inner face 254 of the first member248. As shown, in one embodiment, the risers 256 are D-shaped with theirflat face 257 oriented towards the outside edge of the first member 248and their rounded face 259 oriented towards the center of the firstmember 248. In another embodiment, the risers 256 are D-shaped withtheir rounded face 259 oriented towards the outside edge of the firstmember 248 and their flat face 257 oriented towards the center of thefirst member 248. Alternatively, in other embodiments, the risers 256assume other shapes.

To join the intermediate portions 172 of the legs 164 together with theretainer 124 at the distal end 166 of the retrieval basket 120, theintermediate portions 172 of the legs 164 are initially placed acrossthe inner face 254 of the first member 248. For instance, theintermediate portions 172 of the legs 164 may pass between the risers256. In one embodiment, as illustrated in FIG. 14, the intermediateportions 172 of the legs 164 are side-by-side, but do not cross oneanother. In another embodiment, referring now to FIG. 15, theintermediate portions 172 of the legs 164 cross one another at thedistal end 166 of the retrieval basket 120.

The second member 252 is, in one embodiment, shaped substantiallysimilar to the lower half of a cone. Alternatively, the second member252 assumes other shapes. The second member 252 includes a first end247, a second end 249, a lumen 251 that extends at least from the firstend 247 towards the second end 249, and an inner surface 250. Followingplacement of the intermediate portions 172 of the legs 164 on the firstmember 248, as illustrated in FIG. 14, the second member 252 is attachedto the first member 248, as illustrated in FIG. 16. Initially, therisers 256 of the first member 248 contact the inner surface 250 of thesecond member 252. The risers 256 are forcibly slid along the taperedinner surface 250 of the second member 252 in the direction indicated byarrows 253, thereby providing a force fit between the first member 248and the second member 252. In one embodiment, an ultrasonic weldinghorn, for example, then applies ultrasonic vibrations to the firstmember 248 and to the second member 252. The resulting friction betweenthe risers 256 and the second member 252, caused by the vibrationstherebetween, generates heat. As a result, the risers 256 melt and thefirst member 248 thermally bonds to the second member 252. Theintermediate portions 172 of the legs 164 are, therefore, firmlyencapsulated between the inner face 254 of the first member 248 and thesecond member 252.

FIG. 17 depicts a distal end 166 of a retrieval basket 120 according toanother illustrative embodiment of the invention. According to thisembodiment, the retainer 124 at the distal end 166 of the retrievalbasket 120 includes a lumen 254 and a plurality of openings 258 in fluidcommunication with the lumen 254. The lumen 254 extends from a first end260 of the retainer 124 to a second end 262 of the retainer 124, and mayor may not be completely enclosed axially on all sides. In oneembodiment, the retainer 124 is arch-shaped, and the lumen 254 isdefined by an arch-shaped wall 264. Referring now to FIGS. 18 and 19,the wall 264 includes a roof 268, a first surface 272, and a secondsurface 276. The lumen 254 is open on one side of the retainer 124, i.e.on the side opposite to the roof 268. The first surface 272 includes afirst opening 258A, and the second surface 276 includes a second opening268B. Both openings 258A, 258B are in fluid communication with the lumen254. The retainer 124 may be made of any kind of biocompatible metal,such as, for example, 300 series or 400 series stainless steels.Alternatively, the retainer 124 may be made of biocompatiblethermoplastic.

In one embodiment, referring again to FIG. 17, the intermediate portion172A of the first leg 164A is positioned in the first opening 258A,passes transversely through the lumen 254, and is positioned in thesecond opening 258B. The intermediate portion 172B of the second leg164B is axially positioned in the lumen 254, from at least the first end260 to at least the second end 262 of the retainer 124. The intermediateportion 172B of the second leg 164B is positioned in the space betweenthe first leg 164A and the roof 268. The intermediate portions 172 ofthe legs 164 therefore cross one another at the distal end 166 of theretrieval basket 120.

Alternatively, in another embodiment, and with reference now to FIG. 20,the intermediate portion 172A of the first leg 164A is positioned in thefirst opening 258A and exits the first end 260 of the retainer 124through the lumen 254. The intermediate portion 172B of the second leg164B is positioned in the second opening 258B and exits the second end262 of the retainer 124 through the lumen 254. As such, the legs 164 areside-by-side, but do not cross one another, at the distal end 166 of theretrieval basket 120.

FIG. 21 depicts a distal end 166 of a retrieval basket 120 according toanother illustrative embodiment of the invention. As shown, and withreference also to FIGS. 22 and 23, the retainer 124 at the distal end166 of the retrieval basket 120 is cylindrical. The retainer 124includes a cylinder wall 278 and a lumen 254, extending from a first end260 to a second end 262 of the cylindrical retainer 124. A plurality ofopenings 258 in the cylinder wall 278 extend from the exterior surfaceof the cylinder wall 278 through the cylinder wall 278, and are in fluidcommunication with the lumen 254 of the retainer 124. For example, theretainer 124 includes four openings 258A-, 258B, 258C, and 258D disposedin the cylinder wall 278 of the retainer 124, positioned approximately90 degrees apart from one another. The four openings 258A, 258B, 258C,and 258D are in fluid communication with the lumen 254 of the retainer124. According to this embodiment of the invention, the retainer 124 maybe made of any kind of biocompatible metal, such as, for example, 300series or 400 series stainless steels. Alternatively, the retainer 124may be made of biocompatible thermoplastic.

According to one feature of this embodiment of the invention, referringagain to FIG. 21, the intermediate portion 172A of the first leg 164A ispositioned in the first opening 258A, passes transversely through thelumen 254, and is positioned in the third opening 258C. The intermediateportion 172B of the second leg 164B is positioned in the second opening258B, passes transversely through the lumen 280, and is positioned inthe fourth opening 258D. The intermediate portions 172 of the legs 164cross one another at the distal end 166 of the retrieval basket 120.

Alternatively, in another embodiment, and with reference now to FIG. 24,the intermediate portion 172A of the first leg 164A is positioned in thefirst opening 258A and the second opening 258B of the retainer 124. Theintermediate portion 172B of the second leg 164B is positioned in thethird opening 258C and the fourth opening 258D of the retainer 124. Asillustrated, the legs 164A, 164B are side-by-side, but do not cross oneanother, at the distal end 166 of the retrieval basket 120.

Further, in one embodiment, the cylindrical retainer 124 is swaged orcrimped to tighten down on the intermediate portions 172 of the legs164.

In another aspect, the invention relates to a method for retrievingbiological or foreign material from a body, such as, for example, a bodytract or a body canal, with the medical device 100 according to theinvention. As described above, the retrieval basket 120 of the device100 has an atraumatic distal end 166 and allows for the capture ofmaterial that is located in difficult-to-access areas within the body.Specifically, because the distal end 166 of the retrieval basket 120 isatraumatic, it can make intimate contact with the surface of thepatient's tissue and retrieve materials that are otherwise unrecoverablewith conventional tipped baskets.

In one embodiment, as shown in FIG. 25, an operator inserts at least thedistal end 108 of the medical device 100 into a body tract or a bodycanal 292 (e.g., the urethra) of a patient where the material 296 to bemanipulated, such as a calculus, for example, is located. The operatorinserts the medical device 100 into the body tract 292 with theretrieval basket 120 collapsed within the sheath 116. The distal end 140of the sheath 116 is advanced into the body tract 292 until it ispositioned near the material 296. Referring now to FIG. 26, the operatorextends the legs 164 of the retrieval basket 120, as discussed above,from the distal end 140 of the sheath 116. Accordingly, the retrievalbasket 120 achieves the expanded position. The operator maneuvers theretrieval basket 120 via the handle 112, which is located outside of thepatient's body, until the retrieval basket 120 entraps the material 296,as shown in FIG. 27. Referring now to FIG. 28, the operator secures thematerial 296 within the retrieval basket 120 by moving the retrievalbasket 120 relative to the sheath 116 to close the legs 164 of theretrieval basket 120 around the material 296, as described above. Withthe material 296 so gripped or held by the retrieval basket 120, themedical device 100 and the material 296 are removed from the patient'sbody. Specifically, the operator withdraws the medical device 100 fromthe body along the same path originally used to advance the medicaldevice 100 into the body. Optionally, before the medical device 100 iswithdrawn from the patient's body with the captured material 296, thematerial 296 may be broken apart by, for example, laser energy orlithotripsy. Mechanisms for breaking up the material 296 before itsremoval from the body may be part of the medical device 100 or they maybe separate tools/devices that are also inserted into the body andutilized at the appropriate time during the procedure of removing thematerial 296.

The material 296 that may be captured with the medical device 100according to the invention includes any biological or foreign material.For example, the material 296 may be a kidney stone, a ureteral stone, aurethral stone, a urinary bladder stone, a gallbladder stone, or a stonein the biliary tree. The medical device 100 according to the inventionmay also be used to trap, immobilize, sweep, and/or release materialswithin the body of a patient.

Variations, modifications, and other implementations of what isdescribed herein will occur to those of ordinary skill in the artwithout departing from the spirit and the scope of the invention. Theinvention is not to be defined only by the preceding illustrativedescription.

What is claimed is:
 1. A retrieval basket, comprising: a plurality oflegs; and a U-shaped retainer positioned at a distal end of theretrieval basket and coupled to the plurality of legs, the U-shapedretainer including a lumen defined by an arch-shaped wall having a roofextending between first and second surfaces of the arch-shaped wall,wherein the arch-shaped wall and first and second surfaces are a singlecontinuous member, the U-shaped retainer further including a firstopening defined and encircled by the first surface of the arch-shapedwall and a second opening defined and encircled by the second surface ofthe arch-shaped wall, wherein the first opening includes a continuousclosed perimeter completely surrounded by the first surface, and whereinthe second opening includes a continuous closed perimeter completelysurrounded by the second surface; wherein the plurality of legs areretained within the lumen and the first and second openings, wherein thelumen extends from a first side surface of the U-shaped retainer to asecond side surface of the U-shaped retainer and is completely openopposite the roof from the first side surface to the second sidesurface, and wherein the U-shaped retainer is completely open on eachside surface opposite the first and second side surfaces of the U-shapedretainer.
 2. The retrieval basket of claim 1, wherein an intermediateportion of a first leg is retained within the lumen, and an intermediateportion of a second leg extends through the first and second openingsand is transverse to the intermediate portion of the first leg.
 3. Theretrieval basket of claim 2, wherein the intermediate portion of thefirst leg is disposed between the intermediate portion of the second legand the roof of the arch-shaped wall.
 4. The retrieval basket of claim1, wherein an intermediate portion of a first leg extends through thefirst opening and the lumen, and an intermediate portion of a second legextends through the second opening and the lumen.
 5. The retrievalbasket of claim 4, wherein the intermediate portion of each of the firstand second legs includes a bend in the lumen.
 6. The retrieval basket ofclaim 1, wherein the first opening faces the second opening.
 7. Theretrieval basket of claim 4, wherein the first leg and the second leg donot intersect each other at the distal end of the retrieval basket. 8.The retrieval basket of claim 1, wherein an axis extending through thefirst and second openings extends is transverse to a longitudinal axisof the lumen.
 9. A retrieval basket, comprising: a plurality of legs;and a U-shaped retainer positioned at a distal end of the retrievalbasket and coupled to the plurality of legs, the U-shaped retainerincluding a lumen defined by an arch-shaped wall having a roof extendingbetween first and second surfaces of the arch-shaped wall, the U-shapedretainer further including a first opening and a second opening, whereinthe first and second openings are defined and encircled by oppositesides of the arch-shaped wall, wherein the first and second openings arein communication with the lumen, wherein the first opening includes acontinuous closed perimeter completely surrounded by the first surface,and wherein the second opening includes a continuous closed perimetercompletely surrounded by the second surface; wherein an intermediateportion of a first leg is retained within the lumen, and an intermediateportion of a second leg extends through the first and second openingsand is transverse to the intermediate portion of the first leg, whereinthe lumen extends from a first side surface of the U-shaped retainer toa second side surface of the U-shaped retainer and is completely openopposite the roof from the first side surface to the second sidesurface, wherein the distance between the intermediate portion of thefirst leg and the roof is less than the distance between theintermediate portion of the second leg and the roof.
 10. The retrievalbasket of claim 9, wherein the intermediate portion of the first leg isaxially positioned within the lumen.
 11. The retrieval basket of claim9, wherein the intermediate portion of the first leg is disposed betweenthe intermediate portion of the second leg and the roof.
 12. Theretrieval basket of claim 9, wherein the first opening is defined by afirst surface of the arch-shaped wall, and the second opening is definedby a second surface of the arch-shaped wall.
 13. A retrieval basket,comprising: a plurality of legs; and a U-shaped retainer positioned at adistal end of the retrieval basket and coupled to the plurality of legs,the U-shaped retainer including a lumen defined by an arch-shaped wallhaving a roof extending between first and second surfaces of thearch-shaped wall, the U-shaped retainer further including a firstopening and a second opening, wherein the first and second openings aredefined by opposite sides of the arch-shaped wall, and wherein the firstand second openings are in communication with the lumen, and wherein thefirst opening includes a continuous closed perimeter completelysurrounded by the first surface, and wherein the second opening includesa continuous closed perimeter completely surrounded by the secondsurface; wherein an intermediate portion of a first leg extends throughthe first opening and the lumen, and an intermediate portion of a secondleg extends through the second opening and the lumen, wherein the lumenextends from a first side surface of the U-shaped retainer to a secondside surface of the U-shaped retainer and is completely open oppositethe roof from the first side surface to the second side surface, whereinthe first and second legs do not intersect.
 14. The retrieval basket ofclaim 13, wherein the intermediate portion of each of the first andsecond legs includes a bend in the lumen.
 15. The retrieval basket ofclaim 14, wherein the first opening faces the second opening.
 16. Theretrieval basket of claim 13, wherein the first and second openings areencircled by opposite sides of the arch-shaped wall.